cpython/Parser/bitset.c at pythoncapi · pythoncapi/cpython · GitHub

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/* Bitset primitives used by the parser generator */

#include "pgenheaders.h"

#include "bitset.h"

bitset

newbitset(int nbits)

{

int nbytes = NBYTES(nbits);

bitset ss = (char *)PyObject_MALLOC(sizeof(BYTE) * nbytes);

if (ss == NULL)

Py_FatalError("no mem for bitset");

ss += nbytes;

while (--nbytes >= 0)

*--ss = 0;

return ss;

}

void

delbitset(bitset ss)

{

PyObject_FREE(ss);

}

int

addbit(bitset ss, int ibit)

{

int ibyte = BIT2BYTE(ibit);

BYTE mask = BIT2MASK(ibit);

if (ss[ibyte] & mask)

return 0; /* Bit already set */

ss[ibyte] |= mask;

return 1;

}

#if 0 /* Now a macro */

int

testbit(bitset ss, int ibit)

{

return (ss[BIT2BYTE(ibit)] & BIT2MASK(ibit)) != 0;

}

#endif

int

samebitset(bitset ss1, bitset ss2, int nbits)

{

int i;

for (i = NBYTES(nbits); --i >= 0; )

if (*ss1++ != *ss2++)

return 0;

return 1;

}

void

mergebitset(bitset ss1, bitset ss2, int nbits)

{

int i;

for (i = NBYTES(nbits); --i >= 0; )

*ss1++ |= *ss2++;

}

cpython/Parser/bitset.c at pythoncapi · pythoncapi/cpython · GitHub

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